body {
  margin: 0;
  padding: 0;
  font-family: Helvetica Neue,Helvetica,PingFang SC,Hiragino Sans GB,Microsoft YaHei,\\5FAE\8F6F\96C5\9ED1,Arial,sans-serif;
  line-height: 1.5;
  color: #333;
  background-color: #fff;
  font-size: .24rem;
}
#topbox{
  position: relative;
  margin:0 auto;
  max-width: 10rem;
}
